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Inverse Heat Transfer Problem of Thermal Contact Conductance Estimation in Periodically Contacting Surfaces

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Journal of Thermal Science 2009年第2期18卷 150-159页

作者： M.H.shojaeefard k.Goudarzi M.sh.Mazidi Dept. of Mechanical Engineering Iran University of Science and Technology

The problems involving periodic contacting surfaces have different practical applications. An inverse heat conductionproblem for estimating the periodic Thermal Contact Conductance (TCC) between one-dimensional, constantproperty contacting solids has been investigated with conjugate gradient method (CGM) of function *** method converges very rapidly and is not so sensitive to the measurement errors. The advantage of thepresent method is that no a priori information is needed on the variation of the unknown quantities, since the solutionautomatically determines the functional form over the specified domain. A simple, straight forward techniqueis utilized to solve the direct, sensitivity and adjoint problems, in order to overcome the difficulties associatedwith numerical methods. Two general classes of results, the results obtained by applying inexact simulatedmeasured data and the results obtained by using data taken from an actual experiment are presented. In addition,extrapolation method is applied to obtain actual results. Generally, the present method effectively improves theexact TCC when exact and inexact simulated measurements input to the analysis. Furthermore, the results obtainedwith CGM and the extrapolation results are in agreement and the little deviations can be negligible.

关键词： thermal contact inverse problem conjugates gradient method

Characteristic Assessment of Stabilized Polyacrylonitrile Nanowebs for the Production of Activated Carbon Nano-Sorbents

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Chinese Journal of Polymer Science 2014年第4期32卷 449-457页

作者： S.Rafiei B.Noroozi sh.Arbab A.k.Haghi Department of Textile Engineering University of Guilan

Polyacrylonitrile （PAN） nanofibers with average diameter of 300 nm were produced by electro-spinning. The nanofibers were stabilized at different temperatures in the range of 180-270 ℃in several duration times and heating rates. Fourier transforms infrared （FTIR） spectroscopy, differential scanning calorimetry （DSC） and X-ray diffraction （XRD） analyzing techniques were employed to measure the extent of stabilization reaction. By all procedures, the ranges of temperature and duration time recommended were about 250-270 ℃ and 1-2 h, respectively. Increasing the activation temperature from 800 ℃ to 1200 ℃ caused porosity and pore volume development up to 60% and 0.532 cm3/g, respectively. Pore width of all samples was calculated to be about 0.7 nm confirming micro-pore structure of the produced PAN based activated carbon nanofibers. Comparing dye adsorption for different adsorbents including chitin and granular activated carbon （GAC） showed the highest efficiency for the produced activated carbon nanofibers （ACNFs）.

关键词： Polyacrylonitrile Electro-spinning Stabilization Activated carbon nanofibers Adsorbent.

SLOW PELLETING COAGULATION OF POLYMER LATEX EMULSION

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Chinese Chemical Letters 1996年第3期7卷 297-298页

作者： Li, YM Chen, MW Xu, GJ Ou, sh Wang, k ZHEJIANG UNIV DEPT POLYMER SCI & ENGNHANGZHOU 310027PEOPLES R CHINA

In this paper, slow pelleting flocculation of polymer latex consisting of butadiene, styrene and methyl methacrylate(MBS) were investigated, using aqueous H2SO4 as coagulant. It is found that spherical particles with uniform particle size and high bulk density were produced in the narrow range of pH. In order to obtain good particle morphology, well-distributed concentration, temperature and shear field in the coagulating system were required. Polymer latex made from emulsion polymerization often needs to be converted into dry powders. Usually, we simply add excessive coagulant, such as inorganic acid, salt, etc., into latex emulsion to make it coagulate. The particles formed with such method always have irregular shape and high fines content. In recent years, more attention has been paid to the method of getting coagulated particles with satisfactory particle morphology(1-3)].

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Effect of diode size and series resistance on barrier height and ideality factor in nearly ideal Au/n type-GaAs micro Schottky contact diodes

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Chinese Physics B 2010年第10期19卷 477-484页

作者： M. A. Yeganeh sh. Rahmatallahpur A. Nozad R. k. Mamedov Faculty of Physics Baku State University Academic Zahid Xlilov Küsi-23 AZ 1148 Iran Material Research School POB 55515196 Binab Iran

Small high-quality Au/n type-GaAs Schottky barrier diodes （SBDs） with low reverse leakage current are produced using lithography. Their effective barrier heights （BHs） and ideality factors from current-voltage （I-V） characteristics are measured by a Pico ampere meter and home-built I-V instrument. In spite of the identical preparation of the diodes there is a diode-to-diode variation in ideality factor and barrier height parameters. Measurement of topology of a surface of a thin metal film with atomic force microscope （AFM） shows that Au-n type-GaAS SD consists of a set of parallel-connected micro and nanocontacts diodes with sizes approximately in a range of 100-200 nm. Between barrier height and ideality factor there is an inversely proportional dependency. With the diameter of contact increasing from 5 μm up to 200 μm, the barrier height increases from 0.833 up to 0.933 eV and its ideality factor decreases from 1.11 down to 1.006. These dependencies show the reduction of the contribution of the peripheral current with the diameter of contact increasing. We find the effect of series resistance on barrier height and ideality factor.

关键词： Schottky barrier diodes conducting probe-atomic force microscope barrier height andideality factor

Selective Dealumination of ZSM-5 by Hydrothermal Treatment

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Chinese Chemical Letters 1998年第4期9卷 397-400页

作者： Zhang, k Zhang, HB Xiang, sh Liu, SY Li, HX He, F Nankai Univ Dept Chem Catalysis Lab Tianjin 300071 Peoples R China Tianjin Univ State Key Lab C Chem Tianjin 300072 Peoples R China

We studied the factors affecting the framework aluminium distribution in the ZSM-5 structure by hydrothermal treatment under different conditions. (27)AlMASNMR, XPS and chemical analysis revealed that with steaming at lower water vapor pressure, the framework aluminium located at the external surface is less stable. Steaming at higher water vapor pressure is beneficial in removing the framework Al in HZSM-5, and especially helpful in removing that located at the internal surface of HZSM-5. By changing steaming conditions, one may control the framework aluminium distribution in the HZSM-5 structure.

关键词： selective dealumination water vapor pressure steaming HZSM-5

Effect of porosity on active damping of geometrically nonlinear vibrations of a functionally graded magneto-electro-elastic plate

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Defence Technology（防务技术） 2022年第6期18卷 891-906页

作者： L.sh Esayas Subhaschandra kattimani Department of Mechanical Engineering National Institute of Technology KarnatakaSurathkal575025India

This paper investigates the effect of porosity on active damping of geometrically nonlinear vibrations(GNLV)of the magneto-electro-elastic(MEE)functionally graded(FG)plates incorporated with active treatment constricted layer damping(ATCLD)*** perpendicularly/slanted reinforced 1-3 piezoelectric composite(1-3 PZC)constricting *** constricted viscoelastic layer of the ATCLD is modeled in the time-domain using Golla-Hughes-Mc Tavish(GHM)*** types of porosity distribution in the porous magneto-electro-elastic functionally graded PMEE-FG plate graded in the thickness *** the coupling effects among elasticity,electrical,and magnetic fields,a three-dimensional finite element(FE)model for the smart PMEE-FG plate is obtained by incorporating the theory of layer-wise shear *** geometric nonlinearity adopts the von k arm an *** study presents the effects of a variant of a power-law index,porosity index,the material gradation,three types of porosity distribution,boundary conditions,and the piezoelectric fiber’s orientation angle on the control of GNLV of the PMEE-FG *** results reveal that the FG substrate layers’porosity significantly impacts the nonlinear behavior and damping performance of the PMEE-FG plates.

关键词： Nonlinear vibration Magneto-electro-elastic(MEE)plates Active treatment constricted layer damping(ATCLD) Porosity distribution Porous functionally graded

Patient care during interfacility transport:a narrative review of managing diverse disease states

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World Journal of Emergency Medicine 2023年第1期14卷 3-9页

作者： Quincy k.Tran Francis O’Connell Andrew Hakopian Marwa sh Abrahim kamilla Beisenova Ali Pourmand Department of Emergency Medicine University of Maryland School of MedicineBaltimore 21201USA Program in Trauma the R Adams Cowley Shock Trauma CenterUniversity of Maryland School of MedicineBaltimore 21201USA Department of Emergency Medicine George Washington University School of Medicine and Health SciencesWashington DC 20037USA

BACkGROUND:When critically ill patients require specialized treatment that exceeds the capability of the index hospitals,patients are frequently transferred to a tertiary or quaternary hospital for a higher level of ***,appropriate and efficient care for patients during the process of transport between two hospitals(interfacility transfer)is an essential part of patient *** medical adverse events may occur during the interfacility transfer process,there have not been evidence-based guidelines regarding the equipment or the practice for patient care during ***:We conducted searches from the PubMed,Cumulative Index of Nursing and Allied Health(CINAHL),and Scopus databases up to June *** reviewers independently screened the titles and abstracts for *** that were not in the English language and did not involve critically ill patients were ***:The search identified 75 articles,and we included 48 studies for our narrative *** studies were observational ***:The review provided the current evidence-based management of diverse disease states during the interfacility transfer process,such as proning positioning for respiratory failure,extracorporeal membrane oxygenation(ECMO),obstetric emergencies,and hypertensive emergencies(aortic dissection and spontaneous intracranial hemorrhage).

关键词： Critically ill patients Interfacility transfer Interhospital transfer Extracorporeal membrane oxygenation Obstetric emergencies Hypertensive emergencies

Thermo-economic analysis of the performance of the combined system with evacuated tube collectors

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Clean Energy 2023年第2期7卷 242-252页

作者： Ghassan Fadhil Smaisim Salema k.Hadrawi Azher M.Abed Hasan sh.Majdi Ali shamel Department of Mechanical Engineering Faculty of EngineeringUniversity of Kufa54001Iraq Nanotechnology and Advanced Materials Research Unit(NAMRU) Faculty of EngineeringUniversity of Kufa54001Iraq Refrigeration and Air-conditioning Technical Engineering Department College of Technical EngineeringThe Islamic UniversityNajaf54001Iraq Computer Engineering Department Imam Reza UniversityMashhadIran Department of Air Conditioning and Refrigeration Al-Mustaqbal University CollegeBabylon51001Iraq Department of Chemical Engineering and Petroleum Industries Al-Mustaqbal University CollegeBabylon51001Iraq Department of Chemistry Ardebil BranchIslamic Azad UniversityArdebilIran

Using combined cooling,heat and power systems can be an appropriate substitute for preventing emissions of pollutants and excessive consumption of fossil *** renewable energy in these systems as a source of power generation can be an appropriate substitute for fossil-fuel-based ***,in this paper,cogeneration cooling,heat and power systems based on gas-fired internal combustion engines with a solar-thermal system with evacuated tube collectors have been modelled and thermo-economic analysis has been done to compare fossil-fuel-based *** required rate of heat to supply the hot water is 50 *** the studied system,the internal combustion engine produces electrical ***,the solar-thermal system with evacuated tube collectors and the gas-burning generator provide the thermal energy required by the studied building and the primary stimulus of the absorption chiller for *** this study,two different scenarios are conducted in states considering simultaneous production systems and regardless of this environmental and thermo-economic analysis *** results showed that the efficiency of the studied system was 60% in summer and 56% in winter.

关键词： combined cooling,heat and power thermo-economic analysis evacuated tube collectors environmental analysis solar-thermal energy

Modelling and optimization of combined heat and power system in microgrid based on renewable energy

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Clean Energy 2023年第4期7卷 735-746页

作者： Ghassan F.Smaisim Azher M.Abed Salema k.Hadrawi Hasan sh.Majdi Ali shamel Department of Mechanical Engineering Faculty of EngineeringUniversity of Kufa54001Iraq Nanotechnology and Advanced Materials Research Unit(NAMRU) Faculty of EngineeringUniversity of Kufa54001Iraq Air Conditioning and Refrigeration Techniques Engineering Department Al-Mustaqbal University CollegeBabylon51001Iraq Refrigeration and Air-conditioning Technical Engineering Department College of Technical EngineeringThe Islamic UniversityNajafIraq Department of Chemical Engineering and Petroleum Industries Al-Mustaqbal University CollegeBabylon 51001Iraq Department of Chemistry Ardebil BranchIslamic Azad UniversityArdebilIran

Due to the short distance between the sources of production and consumption,microgrids(MGs)have received considerable attention because these systems involve fewer losses and waste less *** another advantage of MGs is that renewable energy sources can be widely used because these resources are not fully available and can provide a part of the required *** purpose of this research is to model the MG considering the production sources of microturbines,gas turbines and internal combustion *** energies such as wind turbines(WTs)and photovoltaic(PV)cells have been used to provide part of the required power and,because of the lack of access to renewable energy sources at all times,energy reserves such as batteries and fuel cells(FCs)have been *** power of the microturbine,gas turbine,internal combustion engine,FC and battery in this system is 162,150,90,100 and 225 kW,*** modelling the studied system,optimization was done using the imperialist competitive algorithm to minimize production costs and provide maximum thermal and electrical *** maximum production power for PVs is equal to 0.6860 MWh and at this time this value for WTs is equal to 0.3812 MWh,in which case the excess electricity produced will be sold to the grid.

关键词： microgrid energy management system optimization optimal power flow combined heat and power sustainable development